Baseline parameter | Descriptive statistics | Association of parameter with ever meeting HDAS definition* OR (95% CI; p value) | |
Never experienced HDAS (n=161) | At least one occurrence of HDAS (n=125) | ||
Sociodemographic characteristics | |||
Sex | |||
Female | 140 (87.0) | 106 (84.8) | 1 |
Male | 21 (13.0) | 19 (15.2) | 1.2 (0.6 to 2.3; 0.602) |
Ethnicity | |||
Caucasian | 90 (55.9) | 60 (48.0) | 1 |
Asian | 57 (35.4) | 57 (45.6) | 1.5 (0.9 to 2.5; 0.106) |
Other/missing | 14 (8.7) | 8 (6.4) | 0.9 (0.3 to 2.2; 0.745) |
Disease characteristics | |||
Age at diagnosis (years) | |||
<18 | 4 (19.1) | 6 (31.6) | 1 |
≥18 to <45 | 7 (33.3) | 7 (36.8) | 0.5 (0.3 to 1.1; 0.088) |
≥45 | 10 (47.6) | 6 (31.6) | 0.3 (0.1 to 0.6; 0.002) |
Time since diagnosis of SLE (years) | |||
≤5 | 96 (59.6) | 63 (50.4) | 1 |
>5 | 65 (40.4) | 62 (49.6) | 1.5 (0.9 to 2.3; 0.120) |
ACR diagnostic criteria | Per ACR criterion met: | ||
Median no of criteria met at enrolment | 4 (2–9) | 5 (3–9) | 1.7 (1.4 to 2.0; <0.001) |
Specific criteria met: | |||
ANA | 154 (95.7) | 122 (97.6) | 1.8 (0.5 to 7.3; 0.381) |
Arthritis (non-erosive) | 110 (68.3) | 86 (68.8) | 1.02 (0.6 to 1.7; 0.931) |
Discoid rash | 16 (9.9) | 15 (12.0) | 1.2 (0.6 to 2.6; 0.578) |
Haematological disorder | 75 (46.6) | 71 (56.8) | 1.5 (0.1 to 0.9; 0.087) |
Immunological disorders | 118 (73.3) | 113 (90.4) | 3.4 (1.7 to 6.8; <0.001) |
Malar rash | 66 (41.0) | 57 (45.6) | 1.2 (0.8 to 1.9; 0.435) |
Neurological disorder | 6 (3.7) | 14 (11.2) | 3.3 (1.2 to 8.7; 0.019) |
Oral ulcers | 56 (34.8) | 48 (38.4) | 1.2 (0.7 to 1.9; 0.528) |
Photosensitivity | 58 (36.0) | 39 (31.2) | 0.8 (0.5 to 1.3; 0.393) |
Renal disorder | 37 (23.0) | 71 (56.8) | 4.4 (2.6 to 7.3; <0.001) |
Serositis | 41 (25.5) | 53 (42.4) | 2.2 (1.3 to 3.6; 0.003) |
Autoantibody positivity† | |||
ANA | 118 (73.3) | 119 (95.2) | 7.2 (3.0 to 17.6; <0.001) |
Anti-dsDNA | 87 (54.0) | 112 (89.6) | 7.3 (3.8 to 14.1; <0.001) |
Anti-La | 30 (18.6) | 36 (28.8) | 1.8 (1.0 to 3.1; 0.044) |
Anti-RNP | 28 (17.4) | 38 (30.4) | 2.1 (1.2 to 3.6; 0.010) |
Anti-Ro | 57 (35.4) | 64 (51.2) | 1.9 (1.2 to 3.1; 0.008) |
Anti-Sm | 12 (7.5) | 30 (24.0) | 3.9 (1.9 to 8.0; <0.001) |
Anti-phospholipid antibodies | 61 (37.9) | 60 (48.0) | 1.5 (0.9 to 2.4; 0.087) |
Anti-beta2-GPI | 17 (10.6) | 18 (14.4) | 1.4 (0.7 to 2.9; 0.327) |
Anti-cardiolipin | 56 (34.8) | 54 (43.2) | 1.4 (0.9 to 2.3; 0.147) |
Lupus anticoagulant | 13 (8.1) | 15 (12.0) | 1.6 (0.7 to 3.4; 0.271) |
Other serology | |||
Anti-neutrophil cytoplasmic antibody (any) | 12 (7.5) | 17 (13.6) | 2.0 (0.9 to 4.3; 0.092) |
Positive direct antiglobulin test | 30 (18.6) | 37 (29.6) | 1.8 (1.1 to 3.2; 0.031) |
Rheumatoid factor | 42 (26.1) | 39 (31.2) | 1.3 (0.8 to 2.2; 0.342) |
Hypocomplementemia (low C3 or C4) | 66 (41.0) | 82 (65.6) | 2.7 (1.7 to 4.5; <0.001) |
*Reference group for OR is the absence of the parameter where the reference group is not specified.
†Limited to autoantibodies with a prevalence of ≥10%. Note that if we adjust for anti-dsDNA autoantibody positivity when assessing the association of other autoantibodies with HDAS, only anti-dsDNA and anti-Sm remain associated with increased odds of experiencing HDAS (data not shown).
ACR, American College of Rheumatology; HDAS, high disease activity state, SLEDAI-2K ≥10.